ML19294C154
| ML19294C154 | |
| Person / Time | |
|---|---|
| Site: | West Valley Demonstration Project |
| Issue date: | 09/07/1979 |
| From: | Stampelos J Advisory Committee on Reactor Safeguards |
| To: | Lawroski Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-SM-0160, ACRS-SM-160, NUDOCS 8003070214 | |
| Download: ML19294C154 (6) | |
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'o UNITED STATES NUCLEAR REGULATORY COMMISSION o
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E ADVISORY COMMITTEE ON REACTOR SAFEGUARDS d
o WASHINGTON, D. C. 20555
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September 7,1979 Dr. Lawroski, Chairman Subcommittee on Nuclear Fuel Services REPORTS CONCERNING NUCLEAR FUEL SERVICES, WEST VALLEY, N.Y.
I have prepared the sumaries of the reports (listed below) concerning the West Valley facility. While many of these reports are old, they have been only recently provided to the ACRS.
The reports are for the informa-tion of the Committee and no ACRS action is expected.
I am providing, in addition to the summary, a copy of each of the reports to the Subcommittee members and consultants.
Dr. McCreless has asked that you tell him should you desire to hold a meeting on this project.
REPORTS 1.
" Nuclear Regulatory Staff Interim Safety Evaluation.I", August 1977, Docket No. 50-201, Nuclcar Fuel Services, Inc. and New York State Energy Research and Development Authority, Western New York Nuclear Service Center, West Valley, New York.
2.
" Structural Analyses of the Fuel Receiving Station Pool at the Nuclear Fuel Service Reprocessing Plant", West Valley, New York, May 5,1978, UCRL-52575, Lawrence Livennore Laboratory.
3.
" Seismic Analysis of High Level Neutralized Liquid Waste Tanks at the Western New York State Nuclear Service Center", West Valley, New York, May 1978, UCRL-52485, Lawrence Livermore Laborvory.
4.
" Evaluation of the Safety Associated with '.be %fect in the Pan 8D-2 at West Valley, New York", memo dated March 29, N9, to L. C. Rouse, NRC, from C. J. Haughney, NRC.
5.
Pemo dated May 14, 1979 to R. W. Deuster, NFS, Inc., from L. C. Rouse, NRC, with comments on the reports:
" Structural Analyses of the Fuel Re-ceiving Station Pool at the Nuclear Fuel Service Reprocessing Plant, West Valley, New York", March 7, 1979, UCRL 52575, and "Effect of Earthquake on Spent Fuel Storage Pool at West Valley", May 14, 1979.
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2-6.
Memo dated June 20, 1979 to R.W. Duester, NFS, from L. C. Rouse, NRC, with attached comments on the reports:
" Seismic Analysis of High Le'rel Neutralized Liquid Waste Tanks at the NFS Reprocessing Plant, West Valley, New York" March 2,1979, UCRL-52485, and " Staff Comment and Consequence Analysis on the Earthquake Risk from the Neutralized Liquid Waste Tanks at the Western New York Nuclear Service Center, West Valley, Ne< York".
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John Stampelo:;
ACRS Fellow Attachments:
as stated cc:
Subcommittee on NFS Members and Consultants all Attachments ACRS Members w/ summaries w/o reports listed above R. F. Fraley M. W. Libarkin T. G. McCreless
1." NRC Regulatory Staff Interim Safety Evaluation I for Nuclear Fuel Services, West Valley, New York (August 197.')
This report provides the NRC Staff's evaluatii of the safety of the present reduced activities at the subject <i e.
The report includes:
consideration of the managment of radioactive wastes a.
b.
storage of spent fuel surveillance of' the reprocessing plant, and c.
d.
present administrative requirements.
Reprocessing operations ceased in early 1972 and Nuclear Fuel Services (NFS) withdrew from commercial nuclear fuel reprocessing on September 22, 1976. The NFS fuel storage pool contains about 170 MT (about 70% of capacity) of used fuel.
Fuel was last received in 1975 with no plans for receiving any additional fuel. The radiation level above the pool (at 1 foot) is from 2 to 5 mR/hr.
Radiation levels in some process cells are as high as 100 R/hr containing from 1,000 to 10,000 curies principally strontium and cesium.
Two onsite high-level ligeid waste tanks contain 600,000 and 12,000 gallons.
No leaks have been detected (as of March 1977) since the tanks were installed.
About 150,000 cubic feet of high-level solid waste (about 500,000 curies) is buried on site. Cranes, cooling systems, fuel-handling cells, etc.
are generally intact although not currently in use.
The NFS Staff consists of about 50 people for the surveillance and management of this dormant fccility.
The NRC Staff has considered the impact of the failure of structures, systems, and components caused by human error, earthquakes, and torna-does.
The NRC Staff has concluded that the Technical Specifications are adequate and there is no undue risk to the pu'olic or employees be-cause of the passive nature of the plant's present activities.
Several additional areas mentioned were:
reduction of the dependence on off-site energy supplies a.
b.
extensive decontamination prior to decommissioning or reuse of the reprocessing facility continued monitoring of an improperly installed off-gas duct c.
(information on air handby system provided February 1976) d.
upgrading of peak horizontal acceleration for the facility to 0.2g, and various reports and assistance on the project from LASL, LLL, ORNL, e.
ERDA, and the New York Geological Survey yet to be performed (Some of these reports are summarized in sections 2, 3, 4 and 5).
The probability _{or the occurrence of a design basis earthquake (0.2 )
9 is about 2 x 10 per year (once in about 5000 years).
This earth-quake, the maximum earthquake appropriate to assume for design purposes at the site, is a modified Mercalli intensity VIII earthquake occurring 23 miles from the site. The NRC Staff concluded '. hat new design and It construction should be based on an earthquake of '.his magnicude.
was unknown, at the time of this report, whether the fuel storage pool could withstand this acceleration. The results of this evaluation are summarized in sections 2, 3, and 5.
The design basis earthquake for this facility can be considered similar to the safe shutdown earth-quake as used in reactor plants considering the obvious differences in these facilities. The NRC Staff concluded that even though some of walls of some hot process cells may yield or crack under seismic activity, the release of radioactivity to the atmosphere is unlikely because of the lack of dispersal mechanisms within the building.
The large high-level waste tanks and vaults " floated" during construc-tion in 1965.
The corrective action, grouting underneath the vault slab to remove bending stresses on the slab, was accepted by the AEC Regulatory Staff when the facilities operating license was issued in April 1966.
The recurrence interval for a tornado of any size at the plant is 3,400 years. The NRC Staff has not yet evaluated the effect of the design basis tornado on the facility (occurrence every 10,000,000 years).
The NRC Staff did conclude, based on available studies, that the risk of release from the process cells due to a tornado is acceptably low.
Additional studies on possible tornado damage are in progress.
2.
5tructural Analyses of the Fuel Receiving Station Pool at the Nuclear Fuel Service Reprocessing Plant, West Valley, New York (UCRL-52575, May 1978)
The report provides a structural assessment of the fuel receiving station pool. This pool. is an embedded structure consisting of a cask unloading cell, fuel storage cell, and water treatment cell.
The pool is 75 ft. long, 36 ft. wide, and 17 ft. high.
Ground The analysis was performed by the finite element technique.
acceleration of up to 0.2g was considered. Results of the seismic and operating load analyses indicated that at 0.16g, one corner of the fuel storage cell'could crack and leak.
It is estimated that this leakage would be above the soil and into the building enclosing the pool.
Analyses of the cask-drop accident indicated that a drop of the cask from the maximum crane hook height will puncture the cask unloading cell floor.
3.
Seismic Analysis of High Level Neutralized Liquid Waste Tanks at the Western New York State Nuclear Service Center, West Valley, New York (UCRL-52485, May 1978)
This report evaluates the seismic integrity of the two 600,000 gallen, carbon steel liquid waste tanks and their reinforced concrete vaults at the West Valley site.
==
Conclusions:==
The tanks will not slide and are of adequate design at or below a.
0.2g ground acceleration.
b.
Reduction in wall thickness due to corrosion could have a signi-ficant effect on the tank's seismic capacity, however, the indi-cated corrosion to date is insignificant for seismic integrity.
Stress corrosion cracking is a potential problem although it should not affect the seismic integrity of the tanks.
Significant cracking of the vault will occur at 0.13 to 0.16g, c.
however, no excessive compressive stresses would occur below 0.2.
9 The concrete is not expected to penetrate the tanks.
The tanks are 70 ft. in diameter and 27 ft. in height.
The tanks are made of ASTM A-201, Grade A carbon steel plate stress relieved in the field.
The sides are nominally 1/2 inch thick with a design corrosion allowance of 1/4 inch.
4.
Evaluation of the Safety Associated with the Defect in the Pan 80-2 at West Valley, New York (March 29,1979)
The steel pan (capacity about 30,000 gallons) which surrounds the bottom of one of the high level liquid waste tanks at the Nuclear fuel Services facility (capacity about 600,000 gallons)leakedwater into the concrete vault during a test of the pan water level in-strumentat ion.
Additionally, it was discovered that the instrument probe is twelve inches shorter than designed and does not extend to the bottom of the vault.
The pan for the spare tank was tested and did not leak.
The NRC Staff recommended that no attempt should be made to repair the defect in the pan without further analysis of the cause and possible effects of the repair.
The tank has not leaked nor have the other barriers been compromised.
Furthermore, the Staff feels it is un-necessary to transfer the stored liquid waste into the spare tank.
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5.
The Effect of an Earthquake on the High Level Waste Storage Tanks and the Fuel Receiving Station Pool at West Valley, New York (NRC letters f rom L. Rouse dated May 14, 1979 and June 20,1979) 1 In the attachments to these letters various NRC consultants supported and generally agreed with the reports UCRL-52575 and UCRL-52485 previously summarized.
The NRC Staff concludes from these analyses that the carbon steel high level waste tanks will remain intact during an earthquake and that there is a negligible possibility that damage to the vaults could result in breaking of the tanks.
Additional comments are listed below.
It is known that the concrete vault structure crackei_during the unplanned floating (buoyancy) during construction.
External water pressure on the vault and only limited influx of water suggests that the cracking is moderate.
The tanks and vaults are completely buried within the silty clay soil and have a minimum of 8 feet of soi'.
overburden covering the vault roof.
The radiolytic decomposition of the high-level liquid waste could produce as much as 5.5 cubic feet of hydrogen per hour.
The production of steam due to evaporation caused by the same radiation is about 3300 cubic feet per hour.
The flammability of hydrogen is not expected to be a problem following a severe earthquake because of the small amount of hydrogen generated in addition to the large amount of steam in the vapor space of the tank.
Potential releases from the high-level liquid waste tanks during an earthquake are expected to be less than 25% of 10 CFR 20 limits of airborne radioactivity for an individual at the closest site boundary.
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